In winding electrode assemblies for use in rechargeable electrochemical cells, care must be taken to present the electrode strip to the arbors in a specific and exact orientation. If an electrode strip is skewed, that is to say not perpendicular to the winding axis of the winding arbors, successive turns of the wound assembly will not exactly overlap each other. Non-overlapping of successive turns is commonly called spiralling and results in an increase in the height of the electrode assembly which in turn causes physical incompatibility between the wound assembly and the cell container.
Prior art approaches to the aforementioned difficulties have provided for a carrier or shuttle mechanism upon which the electrode is carried. The carrier contains a fixed dimensioned open-ended recess into which the electrode strip is inserted. The width of the recess closely approximates the width of the electrode strip in order that the walls of the recess may positively locate the strip for presentation to the winding arbors. The carrier is then advanced along and guided by a fixed guide member to a location proximate the winding arbors.
While this prior art approach has largely met with success in presenting electrode strips to the winding arbors in an orientation which avoids spiralling during winding, this approach has brought certain undesireable consequences. More specifically, the necessity of having the recess of a width very closely approximating the width of the electrode strip, has caused increased difficulty in inserting the electrode in the recess. In fully automated cell assembly lines intended for high volume production, it is often the case that an electrode, when advanced in close proximity to the recess, is slightly misaligned with respect to the recess. This slight misalignment can result in the electrode strip being on top of the recess rather than in it. When this occurs, of course, the electrode strip is presented to the winding arbors by the carrier member in a skewed condition resulting in spiralling during winding of the electrode assembly.
Therefore, it is an object of the present invention to provide an improvement in a machine for winding electrode assemblies of electrochemical cells.
It is another object of the present invention to provide improved means for presenting an electrode strip to the winding arbors of an electrode assembly winding machine.
It is yet another object of the present invention to present an electrode strip to the winding arbors in an unskewed orientation.
It is still another object of the present invention to facilitate insertion of the electrode strip into a recess disposed in a carrier member.